Presence of Other Drugs in Patients Using Buprenorphine Raises Concern

The significant presence of other drugs, most notably marijuana, in patients who have been prescribed buprenorphine for opioid dependence offers treatment professionals an opportunity for important discussions with clients, suggests the chief clinical officer of the drug testing company that has issued a new report on this trend and others.

“This may present an opportunity to have a discussion on why the treatment plan isn't working,” Millennium Health chief clinical officer Angela G. Huskey, PharmD, tells Addiction Professional. “Do we need a different dose of buprenorphine? Do we need more counseling?”

Drug detection among patients receiving the buprenorphine-naloxone combination (Suboxone) for opioid addiction is one of three topics covered in the first Millennium Health Signals Report, an analysis that Huskey says the company will issue periodically with shifting topics depending on what the landscape calls for at any one time.

The buprenorphine conclusions were based on Millennium's retrospective analysis of more than 150,000 urine drug test results for buprenorphine patients from July 1, 2017 to July 1, 2018, testing for 40 illicit drugs, medications and drug metabolites. Marijuana was the drug with the highest percentage of positives in the sample of individuals who were prescribed Suboxone, at 23.28%. The drugs with the next highest percentage of positives in this group were gabapentin (21.34%), alcohol (10.75%) and cocaine (7.07%).

“Use of buprenorphine with alcohol, illicit drugs or benzodiazepines will increase the risk for adverse reactions, including respiratory depression,” Huskey says. Positive tests for other substances also may signal a patient's impending risk of relapse to opioid misuse, she adds.

The analysis found that 95% of the samples from these patients who were prescribed buprenorphine were positive for the opioid agonist, as expected. In about 2% of these samples, however, testing revealed “abnormally high concentrations of buprenorphine and little or no buprenorphine metabolite, suggesting that buprenorphine may have been directly added to the specimen, a form of adulteration.”

Gabapentin use holds steady

The new report also explores trends in the use of gabapentin, which on one hand has been seen as a potential alternative to opioids for pain but also has raised concerns about potential for misuse. A small handful of states have classified gabapentin as a Schedule V controlled substance, the report states.

A retrospective analysis of urine drug tests from Aug. 4, 2014 to June 30, 2018 found that the proportion of positives for non-prescribed gabapentin has held steady for the past five years, at around 10% or just over. States with the highest percentage of positives for non-prescribed gabapentin were Pennsylvania (20%), Tennessee (15%) and West Virginia (15%).

The frequency of positives for non-prescribed gabapentin was 12% in pain management practices and also 12% in addiction treatment centers.

One might have expected steeper increases in non-prescribed use in recent years given the intense attention that gabapentin has received of late. Huskey says it is important to be mindful of maintaining balanced thinking about the drug, understanding its therapeutic potential in pain treatment while also not losing sight of its possible risks.

“Whether the misuse and abuse of gabapentinoids will become a critical health issue remains to be seen,” the report states.

Fentanyl positives soar

Finally, the report documents the soaring rates of non-prescribed fentanyl detection in samples positive for heroin since 2013. Analyzing more than 5 million test results for the period from January 2013 to May 2018, Millennium Health found that the positive rate for non-prescribed fentanyl in heroin-positive specimens increased from 2% in 2013 to 39% in 2018. In states hit hardest by the proliferation of fentanyl, the numbers are staggering: a 90% positive rate for non-prescribed fentanyl in these samples in Iowa last year, with an 89% rate in Kentucky and an 88% rate in Maryland and Massachusetts.

“These results can help inform and focus clinicians, first responders and public health agencies to better leverage various modalities such as medication-assisted addiction treatment, naloxone, and fentanyl-specific messaging as part of ongoing efforts to curb the devastating toll of fentanyl-spiked heroin,” the report states.